Light sources and objects in ARCHICAD Library

From ARCHICAD 18 the Lightworks rendering engine has been replaced to Cinema 4D rendering engine. The parametrisation of the LIGHT command has been changed according to the new rendering engine. This post introduces the structure of the Light sources and objects in the ARCHICAD Library working with the new rendering engine.

In the ARCHICAD Library there are four basic light sources:

Omni Light: simulates uniform rays shining out from a single infinitely small point in space in all directions

Spot Light: simulates light radiating from a single infinitely small point in space and has a cone of influence in a specific direction.

Area Light: simulates a realistic soft lighting distribution from a definable two- or three-dimensional body

Infinite Light: simulates coherent and parallel infinite light rays

The Light objects in the General Light Sources folder use all the functions provided by the Cinema 4D engine (except a few parameters with fixed values). The parameters can be edited on a hierarchic User Interface. These objects use the basic light sources according to the following table:

Light Source

Light Object in ARCHICAD Library

Omni Light

General Light, IES Light with undefined *.ies file

Spot Light

Spot Light

Area Light

Area Light, Window Light

Infinite Light

Sun Object, Parallel Light

Light Objects in ARCHICAD Library

General Light

2D, 3D Geometry: fix center point, light source is rotatable in case of “Illuminate One Direction Only”
is set

Light Source: Omni Light

Effects on the example:

Visible Light: On, Type: Volumetric

Reduce Density over Distance: On

Reduction Starts: 1200mm, Ends: 3000mm

Noisy Visible Light: On

Noise Type: Noise

Spot Light

2D, 3D Geometry: center point and target point can be set

Light Source: Spot Light

Effects on the example:

Fade Out Gradually: On

Visible Light: On, Type: Volumetric

Reduce Density over Distance: On

Reduction Starts: 0mm, Ends: 3000mm

Reduce Density towards Edges: On

Area Light

2D, 3D Geometry: center point and target point can be set

Light Source: Area Light

Settings and Effects on the example:

Area Shape: Sphere

Shape is Visible In Render: On

Shape is Visible In Reflection: On

Noise Illumination: On, Type: Hard Turbulence

Surface Caustics: On

Lens Flare Glow: On

Lens Flare Type: Star 1

Window Light

2D, 3D Geometry: can be fit to window plane, rotatable (for example can be adjusted to skylight)

Light Source: Area Light

Effect on the example:

Illuminate One Direction Only: On

Sun Object

2D, 3D Geometry: center point can be set, fix target point

Light Source: Infinite Light

No effects on the example

Parallel Light

Differs from Sun Object only in editing options

2D, 3D Geometry: fix center point, target point can be set

Light Source: Infinite Light

Effects on the example:

Reflexes: On, Type: Wide Angle

Ignore Specular Channel: On

Illuminate One Direction Only: On

IES Light

2D, 3D Geometry: fix center point, rotatable light source

Light Source: IES Light, if there is no *.ies file loaded in the Library, then Omni Light

Effects on the example:

Surface Caustics: On

Falloff – Reduce Energy over Distance: On

Interior, Street Lamps

The Lamps in the ARCHICAD Library could be divided into three groups by the used light sources:

Omni light source (Desk Lamps, Street Lamps)

Spot light source (Wall Lamps, Ceiling Spot Lamps)

Area light source (Floor Lamps)

These Lamps use the light sources defined in the lightMacro_m, where most of the rendering engine functions have given a fix value (for example: Lens Flare, Noise, Caustics, Visible Light etc…). Only basic light functions are available for the user in these objects:

Absolute Light Intensity (Light Distance or Light Intensity)

Shadow Quality

Representation of the light cone in 2D and 3D

Changes and parametrisation of the GDL light command

The internal engine is still available, this part has not been modified at the LIGHT command compared to ARCHICAD 17:

In the ADDITIONAL_DATA section of the LIGHT command Cinema 4D engine parameter values can be set. If a parameter’s value is not set, the script will run with the default value of the engine. The available Cinema 4D engine parameters have a specific nomenclature, the overview of these parameters (list of parameters, types, defaults, minimum and maximum values) is in the Cinema 4D Documentation.